Presence and localization of molecules related to the cholinergic system in developing rat testis

The presence of cholinergic molecules was recently found in male gametes of different animal species; very little is known from this point of view abo ut the somatic component of the gonad. In the present study, a contribution is given to the localization of some cholinergic-like molecules, such as a cetylcholinesterase (AChE), nicotinic acetylcholine and muscarinic acetylco line (nAchR and mAChR, respectively) receptors during postnatal development of the testis. Maturation stages were checked by use of histochemical stai nings, such as DAPI for nuclear shape changes, and PSA binding to reveal ac rosomal maturation. The distribution of cholinergic-like molecules, reveale d by immunocytochemical methods in both gametes and somatic cells, varied w ith development. Generally, during early stages, molecules immunologically related to AChE, and to mAChR's were mainly found in the interstitial and p eritubular compartment, while, during maturation, they were found in Sertol i cells and in differentiating germ cells. nAChR's were not found in the so matic compartment, except in the blood vessel walls, and were distributed i n mature germ cells, mainly in the flagella. The presence of cholinergic mo lecules in somatic as well as germ cells could play a role in cell-to-cell communications affecting testicular cell differentiation and function.